Automatic cut-off for gas-mains



(No Model.)

G. W. MCKENZIE.

AUTOMATIC GUT-OFF FOB GAS MAINS.

No. 894,597. Patented Dec. 18, 1888.

I I I I 4 inf o P. (9 & 01W 6 kmussxsa ji- PEIERS Pbolo-Ulmgnpher. WM!!! 0 CL UNITED STATES PATENT OFFICE.

GEORGE \V. MCKENZIE, OF VANPORT, ASSIGN OR TO THE BEAVER MANI FACTURING COMPANY, OF BEAVER COI'NTY, PENNSYLVANIA.

AUTOMATIC CUT-OFF FOR GAS-MAINS.

SPECIFICATION forming part of Letters Patent No. 394,597, dated December 18, 1888. Application filed December 19, 1887. Serial No. 258,412. (No model.)

To all whom it may concern.-

Be itknown that I, GEORGE W. MQKENZIE, a citizen of the United States, residing at Vanport, in the county of Beaver and State of Pennsylvania, have invented certain new and useful Improvements in an Automatic Cut-Off for Gas-Mains; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use the same, reference being had to the accompanying drawings, which form a part of this specification.

My invention relates to an improvement in an automatic cut-off for gas service-pipes, the object being to provide a means for automatically cutting off the gas flowing in the service-pipe in the event of the gas being suddenly cut off either by accident to the mains or the source of supply, and which will be likewise automatically operated to insure a flow of gas in the pipes when the defect has been remedied and the supply re-established, thus avoiding the danger of explosions, which would endanger life and propm'ty.

My invention is also adapted for service in detecting leaks in the service-pipes, and its operation in this particular will be hereinafter fully set forth. These objects I accomplish by means of an :qnimratus operated by the pressure of the gas in the mains, which apparatus will be fully set forth and described hereinafter.

In the accompanying drawings, Figure I is a plan view of the improved automatic cutoff for gas'mains constructed in accordance with my inventiml. Fig. 2 is a front elevation of the same. Fig. 3 is a front elevation of a modification of my invention in which is shown the manner of applying my improvement to a gas-pipe placed in a vertical position.

To put my invention into practice with a service-pipe, j, I provide two concave disks, a b, of suitable size and form of construction, the one a having a means for attaching to a T-coupling, 71:, forming a part of the servicepipe j. Secured between these disks a b is a diaphragm, c, of any flexible substance, having attached to the center of the same, by means of a washer, I, and nut m, a short shaft,

(Z. A spiral spring, g, secured about the front portion of this shaft, d, serves to press the diaphragm 1* against the rear disk, at, when there is no pressure of gas acting on the diaphragm c. \Vhen this is the case, the front end of the shaft (Z, is drawn into the projecting boss n of the front disk, I). An opening or passage, f, formed in the center of the rear portion of the shaft (Z, allows the gas traveling through the pipe to act on the diaphragm c, which, being greater in pressure than the spring g, forces the diaphragm against the front disk, b, thereby moving the shaft (1 forward until the same projects a short distance out of the front face of the boss 11. At a short distance to one side of this apparatus I secure in the service-pipej an ordinary plugvalve, 71, to which is attached a weighted lever, '11, the weighted end of which, when the apparatus is set, rests on the projecting portion of the shaft (1.

In operation the pressure of gas in the pipe overcoming the pressure of the spring y forces the diaphragm c against the front disk, I), thus causing the shaft (1 to project a short distance out of the boss 11. The lever i is made to rest on this projecting end, which lever i, when brought in that position, opens the valve 11. Should the pressure of gas in the pipe j become weakened or suddenly have the supply cut off, the spring g moves the shaft (1 back and allows the weighted lever to fall, which revolves the plug of the valve 71 a quarter-revolution, thereby entirely cutting off all further supply of gas until such time as the apparatus is again set, as before described, thus avoiding the danger of gas explosions should the supply of gas return.

By closing all the valves or cocks in the front of the valve 71 when a pressure of gas is in the pipcj, and then closing the valve 11, a test for leakage is obtained. If there is any leakage in the pipes, the shaft (I will gradually move inward by the action of the spring g on the diaphragm c. If, however, there is no leakage, the shaft (1 will remain stationary.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, 1s

1. An automatic cut-off for gas-mains, such as described, consisting of the concave disks ICO a b, havingsecured between the same a diaphragm, c, the pin cl, having an opening, f, through the same for the admission of gas into the chamber formed between the disk 6 and diaphragm c, the spring g, placed about the pin (1, whereby the diaphragm 0 may be held against the disk at when relieved of the pressure, and the valve or cook h, having a weighted arm, '5', attached thereto and supported by the projecting end of the pin (7, substantially as and for the purpose set forth.

2. The combination of the concave disks suitably united together to form an intermediate chamber, andhaving means for coupling the same to a gas service-pipe, a diaphragm secured between the disks, a stem or shaft secured centrally to the diaphragm and having its ends extended through the disks, one end of said stem being provided with a longitudinal passage and lateral outlets which 20 GEORGE \V. MCKENZIE. [L. s]

In presence of- FRANK XV. SMITH, I. A. CARLINE. 

